Improved filling for safes



' UNITED STATES b PATENT OFFICE.

ROBERT A. GHESEBROUGH, OF NEW YORK, N. Y.

IMPROVED FILLING FOR SAFES.

Specification forming part of Letters Patent No. 56,529, dated July 24, 1866.

To all whom it may concern:

Be it known that I, ROBERT A. Cruise- BROUGH, of the city, county, and State of New York, have invented an Improved Filling for Safes, of which the following is a specification.

My invention consists in the use of boneblack as a filling for safes, vaults, or other receptacles intended to be made fire-proof.

Bone-black is made by charring bones. It is one of the Worst conductors of heat I have ever found, and, I claim, superior to anything now used for filling fire-proof safes.

Plaster-of-paris, alum, and other materials now used as safe fillers contain considerable water when filled in the safe, which is given ofi' as vapor when the safe is exposed to a severe heat, thereby rendering its contents liable to damage. Sometimes, also, the amount of moisture contained in the filling is so great as to cause the books and papers contained in the safe to become moldy and damp. By the use of bone-black as a filler the contents of the safe will be always dry whether the safe is exposed to a severe fire or not, and the boneblack is so poor a conductor of heat that in a safe the filling of which was six inches thick, although the outside was heated nearly red hot, the inside temperature, where the books and papers were placed, could not be raised over 200 Fahrenheit.

Bone-black can be exposed to an intense heat without detriment if kept from the air. A red heat makes no perceptible change in it, although a white heat would destroy its decolorizin g properties. It is far superior to charcoal as a filler for safes, because, first, ordinary charcoal from wood is easier to heat through second, underahigh heat it can be destroyed, while bone-black cannot be destroyed by any heat that a safe is liable to be ever subjected to.

To prepare bone-black for filling in between the inner and outer iron or brick walls of a safe or vault, I first grind the bone-black very finein any burr-mill or other machine for grinding, I then beat it in pans over a fire, or by other means, to a heat which is sufficient to expel all moisture therefrom, and while hot I fill it in between the inner and outer walls or" the safe or vault, and, having carefully packed it down firm and hard as possible, close up the aperture between the walls in which the bone-black was introduced.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is

The use of bone-black for filling in between the inner and outer walls of a safe or vault to render the same fire-proof.

ROBT. A. OHESEBROUGH.

Witnesses:

EDWIN F. COREY, Jr. 1%. G. KEARNY. 

